FACTBOX: West Virginia and its presidential primary

(Reuters) - Democratic presidential candidates Hillary Clinton and Barack Obama face off in West Virginia on Tuesday in the state-by-state process to determine the party's nominee for the November election.

Following are some facts about West Virginia:

* Coal seams run through 53 of this mountainous state's 55 counties. Coal mining remains crucial to the state's identity, though the industry employs far fewer of the state's workers than it once did. Pro-environment positions that play well in other parts of the country are often unpopular here.

* Only 17 percent of West Virginia adults hold a college degree, the lowest figure among the 50 U.S. states. West Virginia also ranks near the bottom in median household income and housing value and near the top in poverty levels.

* With a population that is 95 percent white and culturally conservative, Clinton is expected to do well here. Recent public opinion polls show her leading Obama by roughly 30 percentage points.

* Voting begins at 6:30 a.m. EDT (1030 GMT) and concludes at 7:30 p.m. EDT (2330 GMT), with results expected shortly after.

* Democrats have dominated this pro-labor state for the past half-century, though President George W. Bush's nods to the coal industry helped him carry West Virginia in the 2000 and 2004 presidential elections.

SOURCES: Almanac of American Politics, West Virginia Secretary of State, RealClearPolitics, U.S. Census Bureau

(Compiled by Andy Sullivan, editing by Vicki Allen)

(To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/)